scholarly journals Age-related changes of color visual acuity in normal eyes

PLoS ONE ◽  
2021 ◽  
Vol 16 (11) ◽  
pp. e0260525
Author(s):  
Sho Yokoyama ◽  
Yoshiki Tanaka ◽  
Takashi Kojima ◽  
Rie Horai ◽  
Yukihito Kato ◽  
...  

Purpose To evaluate the age-related change in color visual acuity (CVA) in normal eyes. Methods In total, 162 normal eyes (162 subjects, women: 52, men: 110, age range: 15–68 years) with best-corrected visual acuity (BCVA) ≥20/13 were enrolled. Fifteen colors from the New Color Test (chroma 6) were applied to Landolt “C” rings, white point D65 was applied as background, and a luminance of 30 cd/m2 was set for both the rings and the background. These rings were used to measure the chromatic spatial discrimination acuity as the CVA value, while changing the stimulus size. Correlations of the CVA value of each color and age were evaluated. Mean CVA values of all 15 colors (logarithm of the minimum angle of resolution) were compared between age groups in 10-year increments. Results Nine CVA values (red, yellow-red, red-yellow, green, blue-green, green-blue, purple, red-purple, and purple-red) were negatively correlated with age (all p<0.05); the remaining six (yellow, green-yellow, yellow-green, blue, purple-blue, and blue-purple), as well as BCVA were not. The age groups with the best to worst mean CVA values of 15 colors were as follows: 20–29 (mean ± standard deviation, 0.303 ± 0.113), 30–39 (0.324 ± 0.096), 10–19 (0.333 ± 0.022), 50–59 (0.335 ± 0.078), 40–49 (0.339 ± 0.096), and 60–69 (0.379 ± 0.125) years. There were statistically significant differences between mean CVA values of the following groups: 20–29 and 40–49 years; 20–29 and 60–69 years; 30–39 and 60–69 years (all p<0.01). Conclusions The CVA values related to the medium/long-wavelength-sensitive cones were more susceptible to aging than those related to the short-wavelength-sensitive cones. This differed from previous reports, and may be related to the difference in the range of foveal cone function evaluated with each examination.

1977 ◽  
Vol 232 (6) ◽  
pp. E580
Author(s):  
M P Zabinski ◽  
P Biancani

Longitudinal force-length relationship of the rat esophagus was studied in vitro in three age groups: 1 mo, 3 mo, and 12 mo. The length of maximum force development (MFD) occurs at 1.4-1.5 times the in vivo length for all age groups. The active force developed at MFD increases markedly with age. The difference in the active forces in the 3-mo and 12-mo age groups is due to differences in cross section because the active stress of the esophagus in the longitudinal direction is approximately equal for the two age groups. The active stress in the 1-mo-old rats is lower than in the 3-mo-old rats, suggesting an increased contractility of the esophagus with age in this period of development.


2017 ◽  
Vol 11 (03) ◽  
pp. 335-339 ◽  
Author(s):  
Abdurrazaq Olanrewaju Taiwo ◽  
Adebayo Aremu Ibikunle ◽  
Ramat Oyebunmi Braimah ◽  
Omotayo Amidu Sulaiman ◽  
Olalekan Micah Gbotolorun

ABSTRACT Objective: Tooth extraction is a commonly performed procedure in dental clinics. It has been shown that the reasons for and pattern of tooth extraction vary across geographical regions. Few reports on the pattern of extraction among a semi-urban populace exist. To the best of our knowledge, there is no study on the pattern and reasons for tooth mortality from Sokoto, Northwestern Nigeria, which is a semi-urban region. Materials and Methods: A review of the records of patients that had tooth extraction at our center between January 2009 and January 2016, was done. Data such as the age, gender, type of tooth extracted, and reasons for extraction were retrieved and analyzed. Cross tabulations for age and gender were also made. The level of statistical significance was set at P < 0.05. Results: A total of 1167 extractions were performed in 984 patients. An age range of 18–107 years with a mean (±standard deviation) of 34.8 (13.3) was observed. Most of the patients were in the 21–30 years age group accounting for 35.7% of cases. Dental caries and its sequelae (DCS) (631, 54.1%) were the most common reasons for extraction, followed by periodontal disease (192, 16.5%). The difference in proportions of reasons for tooth extraction between the gender was statistically significant (P = 0.02; df = 24). The difference in the reasons for extraction among the age groups was statistically significant (P < 0.001; df = 132). Conclusion: DCS along with periodontal disease were the major reasons for extractions. These are largely preventable causes of tooth extraction; therefore, there is a need for commencement of far-reaching preventative actions.


2000 ◽  
Vol 46 (3) ◽  
pp. 399-403 ◽  
Author(s):  
Daniel Biou ◽  
Jean-François Benoist ◽  
Claire Nguyen-Thi ◽  
Xuan Huong ◽  
Philippe Morel ◽  
...  

Abstract Background: The published reference values for cerebrospinal fluid (CSF) total protein concentrations in children suffer from two major drawbacks: (a) the age-related range often is too broad when applied to the steeply falling concentrations in early infancy; and (b) no values have been published for widely used dry chemistry methods. Methods: We conducted a 2-year retrospective survey of CSF results obtained in a children’s hospital with a dry chemistry-based method set up on the Vitros 700 analyzer. Results: The data related to ambulatory children up to 16 years of age and term neonates with no clinical or biological signs of brain disease (n = 1074). Seven age groups with significantly different CSF protein values were identified, and their age-related percentiles (5th, 50th, and 95th) were determined. On the basis of the upper 95th percentile, from age 0 to 6 months the CSF protein concentrations fell rapidly from 1.08 to 0.40 g/L. A plateau (0.32 g/L) was reached from age 6 months to 10 years, followed by a slight increase (0.41 g/L) in the 10–16 years age range. Conclusions: These results imply that CSF total protein concentrations in the pediatric setting, particularly in infants, must always be interpreted with regard to narrow age-related reference values to avoid false-positive results.


1984 ◽  
Vol 107 (3) ◽  
pp. 346-351 ◽  
Author(s):  
Takashi Yamada ◽  
Motoji Naka ◽  
Ichiro Komiya ◽  
Kazuo Ichikawa ◽  
Toru Aizawa ◽  
...  

Abstract. Age-related alterations in pituitary-thyroid function were studied in 173 female patients with simple goitre and in 70 normal female subjects. They were divided into 4 groups according to age: A group, less than 19 years; B group, 20 to 29 years; C group, 30 to 39 years; D group, 40 to 59 years. Serum triiodothyronine (T3) concentrations decreased progressively but insignificantly with age in female patients with simple goitre and in normal female subjects, whereas serum thyroxine (T4) concentrations remained constant throughout the studied age range. Only in female patients with simple goitre, did basal serum TSH concentrations show a tendency to increase with age. However, thyrotrophin-releasing hormone (TRH)-stimulated increase of serum TSH was progressively augmented with age both in female patients with simple goitre and in normal female subjects; the magnitude of change was greater in the former group. As reflected by acute increases of serum T3 and T4 concentrations, thyroidal responsiveness to endogenous TSH was progressively depressed with age in female patients with simple goitre and in normal female subjects. This age-related thyroidal refractoriness to TSH was more apparent when the changes were expressed as ΔT3(stimulated T3 – basal T3)/ΔTSH (maximum TSH after TRH – basal TSH), and ΔT4(stimulated T4 – basal T4)/ΔTSH. ΔT4/ΔTSH was lower in female patients with simple goitre than in normal female subjects in all age groups. However, the difference was significant only for ΔT4/ΔTSH in group A. Thyroidal responsiveness to exogenous TSH also gradually declined with age in female patients with simple goitre. Our data indicate 1) TRH-stimulated TSH secretion increases with age probably to overcome age-related thyroidal refractoriness to TSH and 2) although the thyroid of patients with simple goitre is slightly less responsive to TSH than that of normal subjects for all age groups, the difference was significant only for young patients.


2021 ◽  
Author(s):  
Yuge Zhang ◽  
Xinglong Zhou ◽  
Mirjam Pijnappels ◽  
Sjoerd M. Bruijn

AbstractBackgroundGait stability has been shown to be affected by age-related mobility problems, but exercise habits may reduce decline in gait stability. Our aim was to evaluate the variability and stability of feet and trunk between older healthy females and young females using inertial sensors.Method20 older females (OF; mean age 68.4, SD 4.1 years) and 18 young females (YF; mean age 22.3, SD 1.7 years) were asked to walk at their preferred speed, while kinematics were measured using inertial sensors on heels and lower back. Spatiotemporal parameters, acceleration characteristics and their variability, as well as trunk stability as assessed using the local divergence exponent (LDE), were calculated and compared between age groups with two-way ANOVA analyses.ResultsTrunk-foot vertical acceleration attenuation, foot vertical acceleration maximum and amplitude, as well as their variability were significantly smaller in OF than in YF. In contrast, for trunk mediolateral acceleration amplitude, vertical acceleration maximum and amplitude, as well as their variability were significantly larger in OF than in YF. Moreover, OF showed lower stability (i.e. higher LDE values) in ML acceleration, ML and VT angular velocity on the trunk.ConclusionThese findings suggest that healthy older females had a lower maximum toe clearance so that were more likely to trip. Moreover, the acceleration of trunk was sensitive to the difference between healthy older and young females, both in variability and stability. Combined, although older adults had exercise habits, our metrics indicate that they were less stable, which may increase the risk of tripping and balance loss.


2021 ◽  
Author(s):  
Takushi Kawamorita ◽  
Hiroshi Uozato ◽  
Tetsuro Oshika ◽  
Kazuno Negishi ◽  
Takashi Fujikado ◽  
...  

Abstract This prospective observational study aimed to evaluate the eye shape and visual function of Japanese people through a multicenter approach and to create a Japanese model eye. Uncorrected and corrected distance visual acuity (UDVA and CDVA, respectively) in the log minimum angle of resolution (logMAR), subjective and objective spherical equivalent values (SE) of ocular refraction, anterior and posterior corneal curvature (ACC and PCC, respectively), anterior and posterior corneal asphericity (ACA and PCA, respectively), central corneal thickness (CCT), anterior chamber depth (ACD), and ocular axial length (AL) were measured in the eyes of 250 participants (mean age = 46.5 ± 18.0 years, range: 20–90 years) across five institutions in Japan. The mean UDVA, CDVA, subjective SE, objective SE, ACC, PCC, ACA, PCA, CCT, ACD, and AL were 0.68, -0.08, -2.42 D, -2.66 D, 7.77 mm, 6.33 mm, -0.31, -0.39, 0.55 mm, 2.92 mm, and 24.78 mm, respectively. Age-related changes and sex-based differences were observed in the visual acuity, refraction, corneal shape, ACD, and AL. Although the sample size needs to be increased, the results of this study can be applied to the development of refractive correction methods and various vision-related fields.


2018 ◽  
Vol 10 (3) ◽  
pp. 40 ◽  
Author(s):  
Richard E. Hicks ◽  
Victoria E. Alexander ◽  
Mark Bahr

How our memory is affected as we age has been given considerable attention over recent decades as we strive to understand the cognitive processes involved. Memory types have been identified as either explicit (declarative - related to episodes or semantics) or implicit (non-declarative – related to procedures, habits, or earlier priming). Studies have identified likely age-related decline in explicit but not implicit memory though there are opposing results suggested from other studies. It is thought cognitive reserve capacities might explain any non-decline as aging individuals use alternative or additional pathways to ‘remember’. This theory might be supported indirectly if older members remember material accurately but take longer to supply answers. In our current study we re-examined whether age-related differences in accuracy and speed of access in memory are present in both implicit and explicit memory processes and we increased the number of experimental age groups (from 2 to 3) - most previous studies have compared just two groups (young, and old). With three groups (young, middle-old, and older aged groups) we can identify trends across the age range towards deterioration or preservation of memory. We examined sixty-six participants (49 females; 17 males) aged 18 to 86 years (M = 50.27, SD = 21.06) from South-Eastern Queensland and divided these into younger (18 to 46 years of age), middle old (50 to 64) and older aged (65+) cohorts. Participants were administered tasks assessing implicit and explicit memory using computer presentations. Consistent with most prior research, no age differences were identified on accuracy in the implicit memory tasks (verbal and non-verbal, including priming), suggesting that memory for implicit material remains preserved. However, on the explicit memory tasks, older adults performed less accurately than the younger adults, indicative of decline in explicit memory as we age. The finding of a decline in explicit memory but no significant decline in implicit memory confirms most earlier research and is consistent with a view of modular decline rather than overall decline in memory with increasing age. In addition, differences found in speed of response in otherwise accurate implicit memory with older respondents significantly slower, suggests possible support for the cognitive reserve hypothesis. 


1981 ◽  
Author(s):  
F C Chao ◽  
D M Kenney ◽  
J L Tullis ◽  
C A Alper ◽  
J E Silbert

Changes in blood coagulation and platelet functions in vivo in healthy smoking and non-smoking individuals of different age groups were studied. Blood samples were obtained on four different occasions (6 months apart during 1978-1980) from each of the 21 smokers and 42 non-smokers (age range 35-79), and analyzed. Statistically significant changes (p < 0.03) associated with cigarette smoking are: 1) increases in platelet count and fibrinogen in plasma; 2) elevation in a platelet procoagulant, platelet factor-3 (PF-3) activity in platelet-poor plasma (PPP); 3) increases in serum levels of α1-antitrypsin, orosomucoid, haptoglobin and properdin factor B; and 4) shortening of the lag period of collagen-induced platelet aggregation. Filtration through Millipore filters removed membrane vesicles which are enriched with PF-3 activity from the PPP. The difference in PF-3 activity in filtered plasma between the smoking and non-smoking groups were no longer statistically significant. The results are consistent with the interpretation that enhanced PF-3 activity in plasma occurs in association with cigarette smoking and results from the liberation into plasma of platelet membranes enriched in PF-3 activity.


2015 ◽  
Vol 21 (3.2) ◽  
pp. 413-416
Author(s):  
Vilma Jūratė Balčiūnienė ◽  
Rosita Lažaunykaitė

Key words: ranibizumab, age-related macular degeneration, central macular thickness. Research objective. To evaluate influence of treatment with vascular endothelial growth factor inhibitor, ranibizumab, for best corrected visual acuity and central macular thickness in patients with neovascular age-related macular degeneration. Materials and methods. In this retrospective study were included treatment – naive patients. Intravitreal injections were performed at Lithuanian University of Health Sciences Kaunas Clinics Eye clinic. In this study were analysed the 24-month morphological and functional outcomes of intravitreal ranibizumab injections. Best corrected visual acuity was meassured using the Snellen chart (Landolt’s rings C optotypes). Optical coherence tomography images were obtained using the spectral – domain OCT (NIDEK RS – 3000 Advance (NIDEK CO LTD, Japan). The central thickness measurements were obtained from macular thickness maps using the digital caliper tool. Results. In this study were included 88 patients. Best corrected visual acuity before treatment was 0.36 ± 0.22. The difference between visual acuity before and after first injection was 0.04 ± 0.22 (p = 0.03). Before fifth injection visual acuity was 0.41 ± 0.21, after – 0.46 ± 0.22 (p = 0.05). Central macular thickness before treatment was 297.81 ± 106.04 μm. The difference between central macular thickness before and after first injection was 85.21 ± 113.37 μm (p &lt; 0.001). Before second injection central macular thickness was 273.57 ± 87.49 μm, after – 234.51 ± 58.96 μm (p = 0.002). Before fourth injection central macular thickness was 237.20 ± 40.87 μm, after – 219.10 ± 42.26 μm (p = 0.04). The mean central macular thickness significantly decreased from 298.15 ± 104.78 to 229.08 ± 56.57 (p &lt; 0.001). In 24 month of treatment the average number of ranibizumab injections was 3.61 ± 1.55. Conclusions. Our study’s results showed that over 24 month best corrected visual acuity improvement was statistically significant after first and fifth injection. Baseline compared with last injection, there was not statistically significant difference. Central macular thickness improvement statistically significant was after first, second and fourth injection. There was statistically significant decreased baseline compared with the last injection. The mean number of ranibizumab injections was 3.61 ± 1.55 in 24 month.


Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 4117-4117
Author(s):  
Roger C. Munro ◽  
Lisa J. Wakeman ◽  
Saad Al-Ismail

Abstract Introduction: There is published evidence which indicates that advancing age may be associated with higher plasma concentrations of fibrinogen. There is also evidence that derived fibrinogen values are significantly higher than Clauss measurements and that this discrepancy is greater in patients receiving warfarin. The purpose of this study was to determine whether age related derived fibrinogen levels are similar in both warfarin and non-warfarin groups. Methods: Venous samples were collected into siliconised glass B-D Vacutainers containing tri-sodium citrate (Ref: 367691) from 1000 patients receiving long term warfarin treatment and an equal number of age-matched patients not receiving warfarin. Genders were equally represented in both groups. Patients in both groups were categorized into 5 years age bands as follows: &lt;40 n=23: 40–44 n=20: 45–49 n=43; 50–54 n=74: 55–59 n=113: 60–64 n=155: 65–69 n=178: 70–74 n=191: 75–79 n=124; 80–84 n=56: 85–89 n=23. Derived fibrinogen was measured in each patient on an ACL300R coagulometer (I L) within 1 hour of collection using IL PT-FIB HS Plus reagent and following the manufacturer’s protocol. Appropriate CLSI guidelines were followed throughout. A normal probability plot of the data was performed to confirm that it did not deviate too much from the normal distribution. Results: The T-test for independent samples using the separate variance estimate showed that there was a statistically significant difference in the mean fibrinogen between patients on warfarin and those not on warfarin (p&lt;0.05) in each group except for the last (85–89 years). There was a statistically significant difference (ANOVA) in the fibrinogen levels of patients of different age in both warfarinised and non-warfarinised groups (p&lt;0.05). The modified least significance procedure in the ANOVA test showed that in the non-warfarin group, most of significant difference in fibrinogen between the different age groups is contributed by the difference between patients under 50 years of age. In the non-warfarin group, it requires an age gap of at least 20 years for the difference in fibrinogen to be statistically significant but in the warfarin group, it only requires an age gap of ten years (p&lt;0.05). Both Linear Regression and Cross Tabulation indicate that the relationship between fibrinogen and age does not vary whether or not the patient is on warfarin. These also show that the effect of age on fibrinogen is not affected by warfarin treatment. Conclusion: Differences or correlations detected in this analysis are of statistical significance but not necessarily clinically significant. Placing age and warfarin treatment in the same model shows that variations in fibrinogen have to be explained by other factors (e.g. technical) not included in the study as only 12% of the error in predicting fibrinogen levels can be reduced by knowing both the age and status of warfarin treatment in individual patients.


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